The research method that runs the greatest risk of collecting evidence that may be unrepresentative of what is generally true is the case study. This is because case studies focus intensively on a single individual, group, or event, which limits the ability to generalize findings to a broader population
. Additionally, non-probability sampling methods such as convenience sampling and voluntary response sampling also carry a high risk of producing unrepresentative samples due to sampling bias, as participants are not randomly selected and may not reflect the diversity of the population
. However, among research methods, the case study is specifically noted for this risk because it inherently focuses on a very limited scope
